Do 64 bit applications require 64 bit Operating System?

Great answers above, but one thing that hasn't been pointed out is that Core Duo is 32-bit, and Core 2 Duo is 64-bit. BOTH processors are dual-core (it's the Core Solo that's only got one processor).

Also, it sounds like there is some confusion about definitions here. Operating systems are the basic set of software which interface with your hardware, not the hardware itself. Vista is an operating system, as are Linux, Macintosh, BSD, UNIX, et cetera. Both applications and operating system imply sofware, whereas system, processor, et cetera imply hardware.

There is a HUGE point in purchasing a dual-core system, as two processors are much faster than just one. But, as has been said, 32-bit OSs (ie Vista 32-bit) will not utilize 64-bit processors to their full ability.

My recommendation: If you're sticking with Windows, either XP or Vista, go for a Core Duo. But if you think you might want to try out Linux, or plan on upgrading to a 64-bit edition of Vista(ie shelling out $xxx extra on Premium x64 or Ultimate), why not go for a Core 2 Duo?

One final note: if you do decide you want to try out Linux (hey, it's free, and LiveCDs won't hurt your Windows installation), feel free to send a message to me, I'd be more than willing to help.

What makes you think that so many of them are supplied with vista 32-bit. (i have seen the 64-bit models) supplied with Vista 64-bit. But outside of that you may still notice a difference in some of the individual applications. While your system as a whole may not be able to take advantage of the 64bit architecture, programs like Adobe, or certain games have been built tp recognize these processors and act accordingly.

64 bit apps can not work on a 32 bit operating system....but 32 bit apps can work on a 64 bit operating system....

Even though with a 32 bit os, your not using the full potential of the cpu, you are still getting way higher speeds than a single core.....

I had a amd 64 3200+, not a dual core chip, and benchmarked it against a dual core with a 32 os, his cpu blew mine away in the benchmarking program!

yes, you must have a 64-bit OS for your 64-bit apps to work.

however, you dont need 64-bit apps, if you do have a 64-bit OS.

The microsoft world though is not ready fro 64-bit. Want to get the power outta that C2D, install Linux, or FreeBSD on it..

(or..go buy a mac w/ Leopard on it)..

sixty 4 bit is swifter 32 x 2 = sixty 4, do the mathematics, can use extra memory, 32 bit purely ever use 3.5 GB, sixty 4 bit can use upto 32 GB, no longer that you want it. Run homestead windows 7 replace adviser , downloadable from microsoft to confirm if hardware is compliant to run sixty 4 bit?